HOTSPOT
A company has an Office 365 tenant. You use the domain contoso.com for both email and session initiation
protocol (SIP) addresses. You plan to deploy Skype for Business Online and enable federation for all Skypeusers.
You need to create a DNS record to support Skype for Business Online federation.
How should you configure the record? To answer, select the appropriate option from each list in the answer
area.
NOTE: Each correct selection is worth one point.
Hot Area:
Answer: 
Explanation:
https://support.office.com/en-us/article/Create-DNS-records-for-Office-365-using-Windows-basedDNS-9eec911d-5773-422c-9593-40e1147ffbde
Add the SIP SRV record for Skype for Business Online web conferencing.
On the DNS Manager page for your domain, go to Action > Other New Records.
To find this page for your domain, see Find your DNS records in Windows-based DNS.
In the Resource Record Type window, choose Service Location (SRV), and then click Create Record.
In the New Resource Record dialog box, make sure that the fields are set to precisely the following values:
Service: _sip
Protocol: _tls
Priority: 100
Weight: 1
Port: 443
Target (Hostname): sipdir.online.lync.com
The question is: You need to create a DNS record to support Skype for Business Online federation
Add the SIP SRV record for Skype for Business Online federation
On the DNS Manager page for your domain, go to Action > Other New Records.
To find this page for your domain, see Find your DNS records in Windows-based DNS.
In the Resource Record Type window, choose Service Location (SRV), and then click Create Record.
In the New Resource Record dialog box, make sure that the fields are set to precisely the following values:
Service: _sipfederationtls
Protocol: _tcp
Priority: 100
Weight: 1
Port: 5061
Target (Hostname): sipfed.online.lync.com
Correct the proper record is:
Service: _sipfederationtls
Protocol: _tcp
Priority: 100
Weight: 1
Port: 5061
Target (Hostname): sipfed.online.lync.com
Keep in mind that they are asking for federation support
Correct answer –
Service: _sipfederationtls
Protocol: _tcp
Priority: 100
Weight: 1
Port: 5061
Target (Hostname): sipfed.online.lync.com
https://support.office.com/en-us/article/Create-DNS-records-for-Office-365-using-Windows-based-DNS-9eec911d-5773-422c-9593-40e1147ffbde
Correct.
https://support.microsoft.com/en-us/help/2566790/troubleshooting-skype-for-business-online-dns-configuration-issues-in